Pressure relief valves are widely used in motor vehicles to relieve air pressure surges or peaks in the passenger compartment which result for example, when the doors are slammed shut. The valves generally comprise a simple rigid frame or housing which mounts in an aperture in a vehicle body panel. A valve element in the form of a flap is connected to the frame to overlie the aperture in the vehicle body panel. The valve element opens relative to the frame to uncover the aperture to relieve air pressure surges.
A known prior art pressure relief valve for a motor vehicle is illustrated in FIG. 5. The known prior art pressure relief valve 210 includes a rigid frame 212 pivotally mounted to a housing 214 of the pressure relief valve. The rigid frame 212 engages an outer surface 216 of a valve element 218 and pivots relative to the housing 214 when the valve element opens. A spring 220 has a first end connected to the rigid frame 212. A second end of the spring 220 is connected to the housing 214 of the pressure relief valve 210. The spring 220 urges the valve element 218 toward a closed position. The spring 220 extends adjacent to the outer surface 216 of the valve element 218. Therefore, the spring 220 is exposed to the elements outside the pressure relief valve 210.